Material for and method of cleaning leather



Patented June 6, 1939 UNITED STATES MATERIAL FOR AND METHOD OF CLEANING LEATHER Clinton London Campbell,

Noroton Heights,

Conn, assignor to The Viscol Company, Stamford, Oonn., a corporation of Connecticut N0 Drawing. Application March 10, 1938, Serial No. 195,194

4 Claims.

This invention relates to the cleaning of leather, and more particularly the so-called suede or buffed leather.

After leather has been buffed, the buflings become embedded more or less in the fiber, and the satisfactory removal of these bufiings has, for many years, presented a difficult problem. The particles are so fine and cling so tenaciously to the buffed surface of the leather that they cannot be removed efiectively by brushing or the like. The general object of the present invention, therefore, is to provide an improved method for removing these bufiings and any other foreign matter which may be present on the surface of the leather.

In carrying out my improved method, I propose to remove the bufiings and clean the leather by treating the skins in an ordinary tanners wheel or drum by means of a special material in comminuted form.

I have discovered that soft rubber substitutes such as vulcanized oils, are particularly suitable for this purpose.

Vulcanized oils have long been known. As early as the year 1855, Parks describes, in his British Patent No. 2,359 of 1855, how various vegetable oils may be converted into solid elastic compounds by treating with sulphur chloride. Somewhat similar compounds can also be produced by treating such oils with sulphur alone at higher temperatures. Suflicient sulphur is used to convert the oils into a substantially solid state. Such vulcanized oils may also be produced by the slightly modified methods described by Adolph Sommer in his I). S. Patents Nos. 389,020, dated September 4, 1888; 419,726, dated January 21, 1890; 451,531, dated May 5, 1891; and 463,875, dated November 24, 1891, as well as Patent No. 1,151,948 issued August 31, 1915 to F. W. Herbold.

Rubber substitutes or vulcanized oils of this character are also described at page 660 of Vol. IV of Thorpes Dictionary of Applied Chemistry 2). The products resulting from the treatment, of oils with chloride of sulphur are there defined as yellowish, elastic, crumbly substances.

It is possible to produce these vulcanized materials from almost any of the so-called fixed or fatty oils of either animal or vegetable origin.

To provide a substance capable of being used in a tanners wheel for cleaning leather, as above referred to, I take the rubber substitutes made by vulcanizing fatty oils as above described, and grind them, as in a roll mill, until they are reduced to a finely divided or comminuted state. I then place a number of leather skins to be cleaned in a tanners wheel or drum and introduce into such wheel or drum a quantity of the comminuted material. It will be understood that only a small amount of such material is used in comparison with the size of the wheel or drum, so that as the wheel or drum is rotated, the leather skins are tumbled in contact with the loose mass of comminuted material, the skins and material being carried up one side of the wheel or drum and then falling again to the lowest point thereof. By virtue of this tumbling or agitating action, all portions of the surface of the leather are brought into close contact with the mass of comminuted material, or, in other words, the surface is subjected to an action somewhat similar to that of securing. I have found that the comminuted vulcanized oil has the peculiar property of picking up the bufiings, dust or other foreign matter from the surface of the leather, and thus thoroughly cleaning it, the dust and foreign matter adhering to the bits of the material.

After the tumbling operation has been continued for a few minutes, the solid door of the drum or wheel is removed, and a grating or screen put in its place. Then, upon further rotation of the drum, the comminuted material, carrying the dust and dirt with it, is discharged through this grating. The leather is left substantially clean, except for a few particles of the comminuted material which may temporarily cling to it, and which can readily be removed by brushing.

In the coloring of suede leather, it is customary to pound into the skins a dry pigment by placing the same in the drum or wheel with the skins. Where this has been done, and the skins are then subjected to my improved cleaning process, such cleaning process results in removing the excess pigment, as well as the buflings and other foreign matter.

While I have described my improved process as particularly adapted for cleaning suede leather, it is, of course, not limited to such use, as it may also be employed for cleaning the surface of other leathers.

What I claim is:

1. The method of cleaning suede leather which comprises subjecting it to the action of a loose mass of small bits of soft, resilient, material consisting essentially of vulcanized oils, said bits having a surface to which particles of dust or the like will adhere.

2. The method of cleaning leather which comprises subjecting it to the action of a loose mass of a solid, elastic vulcanized oil in comminuted form.

3. The method of cleaning suede leather which comprises agitating it while in contact with a loose mass of small bits of soft, resilient, vulcanized oil.

4. The method of cleaning leather which comprises tumbling it in a rotating drum with a loose mass of soft, comminuted, vulcanized oil.

- CLINTON L. CAMPBELL. 

